Communication control method, base station and user terminal

ABSTRACT

In a communication control method, user terminal and processor thereof, a user terminal receives a plurality of identifiers of wireless LAN access points and information on a security key to be used in a wireless LAN communication. The user terminal notifies a base station of first information indicating a successful connection, in response to a successful connection to a predetermined wireless LAN access point indicated by an identifier included in the plurality of identifiers. The user terminal also notifies the base station of second information indicating an unsuccessful connection, in response to an unsuccessful connection to all of the wireless LAN access point indicated by the plurality of identifiers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of U.S. patentapplication Ser. No. 14/761,894 filed Jul. 17, 2015, which is the U.S.National Phase application of International Patent Application No.PCT/JP2014/050439 filed Jan. 14, 2014, which claims benefit of U.S.Provisional Application No. 61/754,093 filed Jan. 18, 2013, the entirecontents of which are incorporated herein by reference.

TECHNICAL FIELD

A present disclosure relates to a communication control method forlinking a cellular communication system with a wireless LAN system, acellular base station thereof, and a user terminal thereof.

BACKGROUND ART

In recent years, a user terminal (so-called dual terminal) including acellular communication unit and a wireless LAN communication unit isbecoming widely used. Further, the number of wireless LAN access pointsoperated by an operator of a cellular communication system increases.

Therefore, in 3GPP (3rd Generation Partnership Project), which is aproject aiming to standardize a cellular communication system,consideration is given to introduction of a technology capable ofstrengthening linkage between a cellular communication system and awireless LAN system (see Non Patent Document 1).

PRIOR ART DOCUMENT Non-Patent Document

-   Non-Patent Document 1: 3GPP contribution “RP-1201455”

SUMMARY

Further, when a user terminal effectively utilizes a wireless LAN accesspoint, it may be possible to disperse a load at a cellular base stationto the wireless LAN access points.

Therefore, the present disclosure provides a communication controlmethod in which a user terminal effectively utilizes a wireless LANaccess point, a user terminal thereof, and a processor for user terminalthereof.

A communication control method according to the disclosure includestransmitting, from a base station to a user terminal, a plurality ofidentifiers of wireless LAN access points and information on a securitykey to be used in a wireless LAN communication, notifying the basestation, by the user terminal, of first information indicating asuccessful connection, in response to a successful connection to apredetermined wireless LAN access point indicated by an identifierincluded in the plurality of identifiers, and notifying the basestation, by the user terminal of second information indicating anunsuccessful connection, in response to an unsuccessful connection toall of the wireless LAN access point indicated by the plurality ofidentifiers.

A user terminal according to the disclosure is configured to connect toa base station, which is configured to perform cellular communication,and includes a receiver and a transmitter. The receiver is configured toreceive, from the base station, a plurality of identifiers of wirelessLAN access points and information on a security key to be used in awireless LAN communication. The transmitter is configured to notify thebase station of first information indicating a successful connection, inresponse to a successful connection to a predetermined wireless LANaccess point indicated by an identifier included in the plurality ofidentifiers, and notify the base station of second informationindicating an unsuccessful connection, in response to an unsuccessfulconnection to all of the wireless LAN access point indicated by theplurality of identifiers.

A processor according to the disclosure for controlling a user terminalis configured to connect to a base station, which is configured toperform cellular communication, and includes a memory communicativelycoupled to the processor and including instructions. When theinstructions are executed by the processor, the processor performsprocesses of receiving, from the base station, a plurality ofidentifiers of wireless LAN access points and information on a securitykey to be used in a wireless LAN communication, and notifying the basestation of first information indicating a successful connection, inresponse to a successful connection to a predetermined wireless LANaccess point indicated by an identifier included in the plurality ofidentifiers, and notifying the base station of second informationindicating an unsuccessful connection, in response to an unsuccessfulconnection to all of the wireless LAN access point indicated by theplurality of identifiers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system configuration diagram according to an embodiment.

FIG. 2 is a block diagram of UE (user terminal) according to theembodiment.

FIG. 3 is a block diagram of eNB (cellular base station) according tothe embodiment.

FIG. 4 is a block diagram of AP (wireless LAN access point) according tothe embodiment.

FIG. 5 is a protocol stack diagram of a radio interface in an LTEsystem.

FIG. 6 is a configuration diagram of a radio frame used in the LTEsystem.

FIG. 7 is a diagram for illustrating an operation environment accordingto the embodiment.

FIG. 8 is a diagram showing a specific example of an AP registrationinformation table according to the embodiment.

FIG. 9 is a diagram showing a specific example of a pairing tableaccording to the embodiment.

FIG. 10 is a diagram showing a specific example of a WLAN non-support UEtable according to the embodiment.

FIG. 11 is a diagram showing a specific example of a connection failureUE table according to the embodiment.

FIG. 12 is an operation sequence diagram according to the embodiment.

DESCRIPTION OF THE EMBODIMENT Overview of Embodiment

A communication control method according to an embodiment is a methodfor linking a cellular communication system with a wireless LAN system.The communication control method comprises: in a cellular base station,a step of storing location information of a wireless LAN access point; astep of acquiring location information of a user terminal connected tothe cellular base station; a step of determining, on the basis of therespective location information of the wireless LAN access point and theuser terminal, whether or not the user terminal is connected to thewireless LAN access point; and a step of transmitting a scan instructionfor the wireless LAN access point to the user terminal when it isdetermined that the user terminal is connected to the wireless LANaccess point.

In an embodiment, the communication control method, further comprises:in the user terminal, a step of scanning the wireless LAN access pointin response to reception of the scan instruction from the cellular basestation; a step of reporting a result of the scan to the cellular basestation; and a step of connecting to the wireless LAN access point whenthe wireless LAN access point is discovered by the scan.

In an embodiment, in the step of determining, the cellular base stationdetermines, on the basis further of at least one of an amount and acategory of traffic transmitted and received by the user terminal,whether or not the user terminal is connected to the wireless LAN accesspoint is determined.

In an embodiment, the communication control method further comprises: astep of inquiring the user terminal, from cellular base station, ofwhether or not a wireless LAN is supported.

In an embodiment, the scan instruction includes an identifier foridentifying the wireless LAN access point.

In an embodiment, the communication control method further comprises: astep of inquiring the user terminal, from the cellular base station, ofwhether there is connection setting information used for secretcommunication with the wireless LAN access point.

In an embodiment, the communication control method, further comprises: astep of requesting issuance of temporary connection setting informationfrom the cellular base station to the wireless LAN access point, whenthe user terminal does not have the connection setting information; anda step of notifying the user terminal from the wireless LAN access pointby way of the cellular base station, of the temporary connection settinginformation issued by the wireless LAN access point in response to therequest.

In an embodiment, the communication control method further comprises: astep of inquiring a service management server from the cellular basestation, of whether or not the user terminal is registered in a servicecapable of using the wireless LAN access point.

In an embodiment, the communication control method further comprises: astep of transmitting authentication information for registering theservice from the cellular base station to the user terminal when theuser terminal is not registered in the service.

A cellular base station according to the embodiment comprises: a storageunit configured to store location information of a wireless LAN accesspoint; and a control unit configured to acquire location information ofa user terminal connected to the cellular base station. The control unittransmits a scan instruction for the wireless LAN access point to theuser terminal when it is determined, on the basis of the respectivelocation information of the wireless LAN access point and the userterminal, to connect the user terminal to the wireless LAN access point.

A user terminal according to the embodiment is a user terminal connectedto a cellular base station, and comprises: a control unit configured toscan the wireless LAN access point response to reception of a scaninstruction for the wireless LAN access point from the cellular basestation. The control unit reports a result of the scan to the cellularbase station. The control unit connects to the wireless LAN access pointwhen the wireless LAN access point is discovered by the scan.

Embodiment

Below, with reference to the drawing, an embodiment in which an LTEsystem being a cellular communication system configured in compliancewith the 3GPP standards is linked with a wireless LAN (WLAN) system willbe described.

(System Configuration)

FIG. 1 is a system configuration diagram according to the presentembodiment. As shown in FIG. 1, the LTE system includes a plurality ofUEs (User Equipments) 100, E-UTRAN (Evolved Universal Terrestrial RadioAccess Network) 10, and EPC (Evolved Packet Core) 20. The E-UTRAN 10corresponds to a radio access network. The EPC 20 corresponds to a corenetwork.

The UE 100 is a mobile radio communication device and performs radiocommunication with a cell with which a connection is established. The UE100 corresponds to the user terminal. The UE 100 is a terminal (dualterminal) that supports both cellular communication scheme and WLANcommunication scheme.

The E-UTRAN 10 includes a plurality of eNBs 200 (evolved Node-Bs). TheeNB 200 corresponds to a base station. The eNB 200 manages one or aplurality of cells and performs radio communication with the UE 100which establishes a connection with the cell of the eNB 200. It is notedthat the “cell” is used as a term indicating a minimum unit of a radiocommunication area, and is also used as a term indicating a function ofperforming radio communication with the UE 100. Further, the eNB 200 hasa radio resource management (RRM) function, a routing function of userdata, and a measurement control function for mobility control andscheduling.

The eNBs 200 are connected mutually via an X2 interface. Further, theeNB 200 is connected to MME/S-GW 500 included in the EPC 20 via an S1interface.

The EPC 20 includes a plurality of MMEs (Mobility ManagementEntities)/S-GWs (Serving-Gateways) 500. The MME is a network node forperforming various mobility controls, for example, for the UE 100, andcorresponds to a controller. The S-GW is a network node that performstransfer control of user data and corresponds to a mobile switchingcenter.

The WLAN system includes WLAN AP (hereinafter, “AP”) 300. The WLANsystem is configured to be in compliance with some IEEE 802.11standards, for example. The AP 300 communicates with the UE 100 in afrequency band (WLAN frequency band) different from a cellular frequencyband. The AP 300 is connected to the EPC 20 via a router, etc. In thepresent embodiment, the AP 300 is operated by an operator of thecellular communication system (the LTE system).

Subsequently, a configuration of the UE 100, the eNB 200, and the AP 300will be described.

FIG. 2 is a block diagram of the UE 100. As shown in FIG. 2, the UE 100includes: antennas 101 and 102; a cellular transceiver (cellularcommunication unit) 111; a WLAN transceiver (WLAN communication unit)112; a user interface 120; a GNSS (Global Navigation Satellite System)receiver 130; a battery 140; a memory 150; and a processor 160. Thememory 150 and the processor 160 configure a control unit. The UE 100may not have the GNSS receiver 130. It is noted that the memory 150 maybe integrally formed with the processor 160, and this set (that is, achipset) may be called a processor 160′.

The antenna 101 and the cellular transceiver 111 are used fortransmitting and receiving a cellular radio signal. The cellulartransceiver 111 converts a baseband signal output from the processor 160into the cellular radio signal, and transmits the same from the antenna101. Further, the cellular transceiver 111 converts the cellular radiosignal received by the antenna 101 into the baseband signal, and outputsthe same to the processor 160.

The antenna 102 and the WLAN transceiver 112 are used for transmittingand receiving a WLAN radio signal. The WLAN transceiver 112 converts thebaseband signal output from the processor 160 into a WLAN radio signal,and transmits the same from the antenna 102. Further, the WLANtransceiver 112 converts the WLAN radio signal received by the antenna102 into a baseband signal, and outputs the same to the processor 160.

The user interface 120 is an interface with a user carrying the UE 100,and includes, for example, a display, a microphone, a speaker, andvarious buttons. Upon receipt of the input from a user, the userinterface 120 outputs a signal indicating a content of the input to theprocessor 160. The GNSS receiver 130 receives a GNSS signal in order toobtain location information indicating a geographical location of the UE100, and outputs the received signal to the processor 160. The battery140 accumulates a power to be supplied to each block of the UE 100.

The memory 150 stores a program to be executed by the processor 160 andinformation to be used for a process by the processor 160. The processor160 includes the baseband processor that performs modulation anddemodulation, and encoding and decoding on the baseband signal and a CPUthat performs various processes by executing the program stored in thememory 150. The processor 160 may further include a codec that performsencoding and decoding on sound and video signals. The processor 160executes various processes and various communication protocols describedlater.

FIG. 3 is a block diagram of the eNB 200. As shown in FIG. 3, the eNB200 includes an antenna 201, a cellular transceiver 210, a networkinterface 220, a memory 230, and a processor 240. The memory 230 and theprocessor 240 configure a control unit. It is noted that the memory 230may be integrally formed with the processor 240, and this set (that is,a chipset) may be called a processor.

The antenna 201 and the cellular transceiver 210 are used fortransmitting and receiving a cellular radio signal. The cellulartransceiver 210 converts the baseband signal output from the processor240 into the cellular radio signal, and transmits the same from theantenna 201. Furthermore, the cellular transceiver 210 converts thecellular radio signal received by the antenna 201 into the basebandsignal, and outputs the same to the processor 240.

The network interface 220 is connected to the neighboring eNB 200 via anX2 interface and is connected to the MME/S-GW 500 via the S1 interface.The network interface 220 may be used for communication with the AP 300via the EPC 20.

The memory 230 stores a program to be executed by the processor 240 andinformation (such as various tables described later) to be used for aprocess by the processor 240. The processor 240 includes the basebandprocessor that performs modulation and demodulation, encoding anddecoding and the like on the baseband signal and a CPU that performsvarious processes by executing the program stored in the memory 230. Theprocessor 240 implements various processes and various communicationprotocols described later.

FIG. 4 is a block diagram of the AP 300. As shown in FIG. 4, the AP 300includes an antenna 301, a WLAN transceiver 311, a network interface320, a memory 330, and a processor 340. It is noted that the memory 330may be integrally formed with the processor 340, and this set (that is,a chipset) may be called a processor.

The antenna 301 and the WLAN transceiver 311 are used for transmittingand receiving the WLAN radio signal. The WLAN transceiver 311 convertsthe baseband signal output from the processor 340 into the WLAN radiosignal and transmits the same from the antenna 301. Further, the WLANtransceiver 311 converts the WLAN radio signal received by the antenna301 into the baseband signal and outputs the same to the processor 340.

The network interface 320 is connected to the EPC 20 via a router, etc.The network interface 320 may be used for communication with the eNB 200via the EPC 20.

The memory 330 stores a program executed by the processor 340 andinformation used for a process by the processor 340. The processor 340includes the baseband processor that performs modulation anddemodulation, and encoding and decoding on the baseband signal and a CPUthat performs various processes by executing the program stored in thememory 330.

FIG. 5 is a protocol stack diagram of a radio interface in the LTEsystem. As shown in FIG. 5, the radio interface protocol is classifiedinto a layer 1 to a layer 3 of an OSI reference model, wherein the layer1 is a physical (PHY) layer. The layer 2 includes a MAC (Media AccessControl) layer, an RLC (Radio Link Control) layer, and a PDCP (PacketData Convergence Protocol) layer. The layer 3 includes an RRC (RadioResource Control) layer.

The PHY layer performs encoding and decoding, modulation anddemodulation, antenna mapping and demapping, and resource mapping anddemapping. Between the PHY layer of the UE 100 and the PHY layer of theeNB 200, data is transmitted via the physical channel.

The MAC layer performs priority control of data, and a retransmissionprocess and the like by hybrid ARQ (HARQ). Between the MAC layer of theUE 100 and the MAC layer of the eNB 200, data is transmitted via atransport channel. The MAC layer of the eNB 200 includes a scheduler fordetermining a transport format (a transport block size, a modulation andcoding scheme and the like) of an uplink and a downlink, and anallocated resource block.

The RLC layer transmits data to an RLC layer of a reception side byusing the functions of the MAC layer and the PHY layer. Between the RLClayer of the UE 100 and the RLC layer of the eNB 200, data istransmitted via a logical channel.

The PDCP layer performs header compression and decompression, andencryption and decryption.

The RRC layer is defined only in a control plane. Between the RRC layerof the UE 100 and the RRC layer of the eNB 200, a control message (anRRC message) for various types of setting is transmitted. The RRC layercontrols the logical channel, the transport channel, and the physicalchannel in response to establishment, re-establishment, and release of aradio bearer. When there is a connection (RRC connection) between theRRC of the UE 100 and the RRC of the eNB 200, the UE 100 is in aconnected state (RRC connected state), otherwise, the UE 100 is in anidle state (RRC idle state).

A NAS (Non-Access Stratum) layer positioned above the RRC layer performssession management or mobility management, for example.

FIG. 6 is a configuration diagram of a radio frame used in the LTEsystem. In the LTE system, OFDMA (Orthogonal Frequency DivisionMultiplexing Access) is applied to a downlink, and SC-FDMA (SingleCarrier Frequency Division Multiple Access) is applied to an uplink,respectively.

As shown in FIG. 6, the radio frame is configured by 10 subframesarranged in a time direction, wherein each subframe is configured by twoslots arranged in the time direction. Each subframe has a length of 1 msand each slot has a length of 0.5 ms. Each subframe includes a pluralityof resource blocks (RBs) in a frequency direction, and a plurality ofsymbols in the time direction. The resource block includes a pluralityof subcarriers in the frequency direction.

Among radio resources allocated to the UE 100, a frequency resource canbe designated by a resource block and a time resource can be designatedby a subframe (or slot).

In the downlink, an interval of several symbols at the head of eachsubframe is a control region mainly used as a physical downlink controlchannel (PDCCH). Furthermore, the remaining interval of each subframe isa region that can be mainly used as a physical downlink shared channel(PDSCH). Furthermore, in the downlink, reference signals such ascell-specific reference signals are distributed and arranged in eachsubframe.

In the uplink, both ends, in the frequency direction, of each subframeare control regions mainly used as a physical uplink control channel(PUCCH). Furthermore, the center portion, in the frequency direction, ofeach subframe is a region that can be mainly used as a physical uplinkshared channel (PUSCH).

Operation According to Embodiment

Next, an operation according to the present embodiment will bedescribed. FIG. 7 is a diagram for explaining an operation environmentaccording to the present embodiment.

As shown in FIG. 7, the AP(s) 300 (AP 300-1 to AP 300-3) is arrangedwithin a coverage of the eNB 200. In the present embodiment, the eNB 200is a macro bases station that manages a cell (macro cell) over a widerange. UE 100-1 to UE 100-3 are connected to a cell of the eNB 200, andperform cellular communication with the eNB 200. When the eNB 200accommodates a large number of UEs 100, a load of the eNB 200 increases.That is, an amount of a radio resource (a resource block, etc.) that canbe allocated by the eNB 200 to each UE 100 decreases.

The AP 300 is operated by an operator of a cellular communication system(in the present embodiment, the LTE system). UE 100-4 is connected tothe AP 300-3, and performs WLAN communication with the AP 300-3. On theother hand, there is no UE 100 to be connected to the AP 300-1 and theAP 300-2.

Hereinafter, an operation of the eNB 200 for dispersing (offloading) theload of the eNB 200 to the AP 300 will be described.

Firstly, the eNB 200 stores the location information (specifically, APregistration information table including the location information) ofeach AP 300 arranged in the cell of the eNB 200. FIG. 8 is a diagramshowing a specific example of the AP registration information table. Asshown in FIG. 8, the AP registration information table includes anidentifier (SSID/ESSID) and location information (longitude, latitude,etc.) of each AP 300 arranged within the cell of the eNB 200.

The AP registration information table is created and updated by anoperator, for example. When the eNB 200 is capable of communicating withthe AP 300, the eNB 200 may acquire the information of the AP 300 toupdate the AP registration information table. For example, the eNB 200may update the AP registration information table on the basis ofinformation on connection availability (power on/off, etc.) of the AP300.

Alternatively, the eNB 200 may update the AP registration informationtable on the basis of a report of whether the scan is successful or not(whether the connection is successful or not), described later. The eNB200 monitors and records a status of the connection availability, anddeletes the AP 300 that has no successful connection record from the APregistration information table. Then, the eNB 200 again monitors thestatus of the successful connection about the deleted AP 300 with aconstant interval (half day, one day, etc.), and when the connection issuccessful, the eNB 200 adds again the AP 300 to the AP registrationinformation table.

Secondly, the eNB 200 acquires the location information (longitude,latitude, etc.) of each UE 100 connected to the cell of the eNB 200. Forexample, the eNB 200 may acquire the location information by the GNSSfrom the UE 100, and may acquire UE location information from a locationinformation management server (E-SMLC: Evolved Serving Mobile LocationCentre) arranged in the EPC 20. Alternatively, the eNB 200 may acquirethe UE location information from UE direction information based onantenna directivity control and UE distance information based ontransmission power control or transmission timing control.

Thirdly, the eNB 200 associates (pairs) the AP 300 with the UE 100adjacent thereto, on the basis of the location information of each ofthe UE 100 and the AP 300. For example, the eNB 200 calculates adistance between the UE 100 and the AP 300, and performs pairing whenthe distance is within a distance that corresponds to a maximumcommunication range of the WLAN.

In the present embodiment, the eNB 200 ranks the distance to the AP 300for each UE 100 in proximity to the AP 300, and sets a priority forconnecting to the AP 300. Specifically, the eNB 200 sets a higherpriority to the UE 100 nearer the AP 300.

For the use for the ranking, the eNB 200 may further acquire an amountand/or a category of traffic transmitted and received by each UE 100connected to the cell of the eNB 200. The amount of traffic may be anamount of actual traffic per unit time, or may be an amount of trafficto be estimated from an amount of allocated radio resource. It ispossible to determine the category of traffic from QoS corresponding toa bearer of the UE 100, for example. The eNB 200 sets a higher priorityto the UE 100 having a larger amount of traffic. Further, the eNB 200sets a higher priority to the UE 100 that transmits and receives atraffic having a lower QoS.

The eNB 200 stores and updates the pairing table in accordance with theresult of the pairing and the set priority (ranking). FIG. 9 is adiagram showing a specific example of the pairing table. As shown inFIG. 9, in the pairing table, the above-described result of the pairingand priority (ranking) are recorded. In FIG. 9, the priority (ranking)is set also to the AP 300, and the priority is set in accordance with adistance to the UE 100 having the highest priority or a distance to anaverage location of each corresponding UE 100, for example.

The eNB 200 regularly updates the pairing table. In this case, when itis assumed that a UE moving speed is mainly at 5 to 7 km/h or slower, amovement of about 20 m in 10 seconds is achieved, and when it issupposed that a maximum communication range of WLAN is about 50 m, itwould be appropriate to update with an interval of 1 to 10 seconds.

Fourthly, the eNB 200 determines, on the basis of the pairing table,whether or not the UE 100 is connected to the paired AP 300. In thepresent embodiment, the eNB 200 determines that the UE 100 having a highpriority is connected to the paired AP 300. The eNB 200 may regularlymake such a determination, and may make such a determination when a loadlevel of the eNB 200 exceeds a threshold value.

It is noted that there may exist UE 100 that does not support WLAN in aplurality of UEs 100 connected to the cell of the eNB 200. Therefore,the eNB 200 may inquire the UE 100 of whether the WLAN is supported andstore a result of the inquiry. A specific example of a table where UEthat does not support WLAN (WLAN non-support UE) is recorded is shown inFIG. 10. The eNB 200 exclude the WLAN non-support UE from connectiontarget to the AP 300 (that is, a pairing target).

Fifthly, the eNB 200 transmits a scan instruction for AP 300, to the UE100 that is determined to be connected to the AP 300. In the presentembodiment, the UE 100 is connected to the AP 300 when the scan issuccessful, and thus, it may be possible to consider that the scaninstruction is an instruction to connect to the AP 300. The scaninstruction includes an identifier (SSID/ESSID) for identifying the AP300 being the connection target of the UE 100.

Then, the eNB 200 receives a report of a scan result from the UE 100,releases a radio resource for the UE 100 that has a successful scan(successful connection), and disconnects the connection. Further, theeNB 200 stores whether the scan is successful or not (whether theconnection is successful or not). FIG. 11 shows a specific example of atable (connection failure UE table) where the UE 100 that has a failedconnection to the AP 300 is recorded.

It is noted that from each of the above-described tables, information onthe UE 100 that disconnects the connection to the eNB 200 is deleted,where appropriate. Further, the eNB 200 updates the pairing table so asto reflect an update of the WLAN non-support UE and an update of theconnection failure UE table.

Next, a detailed example of an operation sequence according to thepresent embodiment will be described. FIG. 12 is an operation sequencediagram according to the present embodiment.

As shown in FIG. 12, in step S101, the eNB 200 selects the UE 100 to beconnected to the AP 300, on the basis of the pairing table.

In step S102, the eNB 200 inquires the UE 100 selected on the basis ofthe pairing table, of the availability of the WLAN support.

In step S103, the UE 100 notifies the eNB 200 of the availability of theWLAN support, in response to the inquiry from the eNB 200.

When the UE 100 does not support the WLAN (step S104; No), in step S105,the eNB 200 registers the UE 100 into the WLAN non-support UE table.

On the other hand, when the UE 100 supports the WLAN (step S104; Yes),in steps S106 and S107, the eNB 200 inquires the service managementserver of whether or not the UE 100 can use the WLAN connection serviceand receives a reply. Such a process will be described in detail in asecond modification of the embodiment. It is noted that the processes insteps S106 and S107 are not essential and thus may be omitted.

In step S108, on the basis of the pairing table, the eNB 200 decides toconnect the UE 100 to the corresponding AP 300. Then, the eNB 200acquires the identifier (SSID/ESSID) of the corresponding AP 300 fromthe AP registration information table.

In step S109, the eNB 200 transmits the scan instruction including theacquired AP identifier (SSID/ESSID), to the UE 100. It is noted that thescan instruction may include a plurality of AP identifiers (SSID/ESSID).

In steps S110 and S111, the UE 100 scans for the AP identifier(SSID/ESSID) included in the scan instruction received from the eNB 200.Specifically, it is determined whether or not to receive a beacon signalcorresponding to the AP identifier (SSID/ESSID) included in the scaninstruction. The UE 100 connects to the AP 300 that is discovered by thescan, when the scan is successful. The description below proceeds, withan assumption, where the scan is successful (that is, the designated AP300 is discovered).

It is noted that the UE 100 may switch the WLAN transceiver 112 to an onstate in accordance with the reception of the scan instruction, when theWLAN transceiver 112 is in an off state at the time when the scaninstruction is received.

In step S112, the UE 100 notifies the eNB 200 of the result of the scan(that is, whether the connection to the AP 300 is successful or not).

The UE 100 starts WLAN communication with the AP 300 in step S114, whenit is successful to connect to the AP 300 (step S113; Yes).

Further, when it is notified of the successful connection to the AP 300(step S115; Yes), in step S116, the eNB 200 releases the radio resourceassigned to the UE 100 and disconnects the connection to the UE 100.Moreover, the eNB 200 deletes the UE 100 from the pairing table.

On the other hand, when it is notified of the unsuccessful connection tothe AP 300 (step S115; No), in step S117, the eNB 200 moves the UE 100from the pairing table to the connection failure UE table.

Conclusion of Embodiment

As described above, in the present embodiment, the eNB 200 stores thelocation information of the AP 300. The eNB 200 acquires the locationinformation of the UE 100 connected to the eNB 200, and on the basis ofthe respective location information of the AP 300 and the UE 100,determines whether or not the UE 100 is connected to the AP 300. Then,when it is determined that the UE 100 is connected to the AP 300, theeNB 200 transmits the scan instruction for the AP 300, to the UE 100.Thus, the UE 100 that is approaching the AP 300 is capable ofdiscovering the AP 300. As a result, it is possible for the UE 100 to beconnected to the AP 300, and thus, it is possible to efficiently use theAP 300 and disperse (offload) the load of the eNB 200 to the AP 300.

In the present embodiment, the UE 100 performs the scan on the AP 300 inresponse to the reception of the scan instruction from the eNB 200, andreports the result of the scan to the eNB 200. Further, the UE 100connects to the AP 300 when the AP 300 is discovered by the scan.Thereby, the eNB 200 is capable of comprehending whether or not the UE100 connects to the AP 300.

In the present embodiment, the eNB 200 determines whether or not the UE100 is connected to the AP 300 on the basis further of the amount and/orthe category of traffic transmitted and received by the UE 100. Thereby,it is possible to efficiently perform a load dispersion to the AP 300.

In the present embodiment, the eNB 200 inquires the UE 100 of whether ornot the WLAN is supported. Thereby, it is possible for the eNB 200 tocomprehend the UE 100 capable of load dispersion to the AP 300.

In the present embodiment, the scan instruction includes an identifierfor identifying the AP 300. Thereby, the UE 100 is capable ofefficiently discovering the AP 300 because it may suffice to scan onlythe AP 300 corresponding to the instructed identifier.

First Modification of Embodiment

In the above-described embodiments, secret communication between the UE100 and the AP 300 has not been particularly considered; however, in thepresent modification, such secret communication is considered.

In the present modification, the eNB 200 inquires, the UE 100 determinedto be connected to the AP 300, of whether there is connection settinginformation used in the secret communication with the AP 300. When suchconnection setting information is not provided in the user terminal, theeNB 200 requests the AP 300 of the connection target to issue temporaryconnection setting information. Then, the temporary connection settinginformation issued by the AP 300 in response to the request from the eNB200 is notified to the UE 100 from the AP 300 via the eNB 200.

Detailed procedures will be described, below.

Firstly, the eNB 200 transmits, to the UE 100, WLAN connection settingconfirmation information for inquiring whether there is a connectionsetting (secret setting) with the AP 300 of the connection target. TheWLAN connection setting confirmation information includes an identifier(SSID/ESSID) of the AP 300 of the connection target.

Secondly, the UE 100 sends back, to the eNB 200, a WLAN connectionsetting response indicating whether there is the connection setting forthe inquired AP 300. The WLAN connection setting response includes theidentifier (SSID/ESSID) of the AP 300 of the connection target.

Thirdly, the eNB 200 transmits issuance request information requestingto issue a temporary connection setting, to the AP 300 of the connectiontarget, when there is no connection setting in the WLAN connectionsetting response. The issuance request information includes MAC-ID ofthe WLAN of the UE 100.

Fourthly, the AP 300 generates the temporary connection settinginformation in response to the issuance request information from the eNB200, and notifies the eNB 200 of the information. The temporaryconnection setting information includes information on the secretsettings (a secret type and a secret key).

Fifthly, the eNB 200 adds the identifier (SSID/ESSID) of the AP 300 tothe temporary connection setting information from the AP 300, andtransfers the same to the UE 100. The eNB 200 may include the temporaryconnection setting information in the above-described scanninginstruction.

Second Modification of Embodiment

In the above-described embodiments, whether the WLAN service isavailable to the UE 100 has not been particularly considered; however,in the present modification, whether the WLAN service is available tothe UE 100 is considered.

In the present modification, the eNB 200 inquires a service managementserver of whether the UE 100 connecting to the cell of the eNB 200 isregistered in a service allowing the use of the AP 300. The eNB 200 maytransmit, from the eNB 200 to the UE 100, authentication information forregistering in the service when the UE 100 is not registered in thatservice.

Detailed procedures will be described, below.

Firstly, the eNB 200 transmits, to the service management server,service registration confirmation information for inquiring whetherthere is the service registration in a WLAN network. The serviceregistration confirmation information includes an identifier (such asMAC-ID) of the UE 100.

Secondly, the service management server sends back, to the eNB 200,service registration information indicating the registration in the WLANservice. The service registration information includes an identifier(such as MAC-ID) of the UE 100.

Thirdly, the eNB 200 transmits a scanning instruction (WLAN connectionrequest) to the UE 100 when there is a service contract in the serviceregistration information from the service management server. On theother hand, when there is no service contract, the eNB 200 does nottransmit the scanning instruction to the UE 100. Alternately, the eNB200 decides to provide a temporary service, and transmits, to the UE100, authentication information for a temporary login setting for theservice, that is, a service authentication key (an authentication ID anda password).

Other Embodiments

Thus, the present disclosure has been described with the embodiments.However, it should not be understood that those descriptions anddrawings constituting a part of this disclosure limit the presentdisclosure. From this disclosure, a variety of alternate embodiments,examples, and applicable techniques will become apparent to one skilledin the art.

In the above-described embodiments, a case where the eNB 200 and the AP300 are a separate device is described; however, the eNB 200 may includea function of the AP 300. That is, the eNB 200 may include a WLANtransceiver.

Further, in the above-described embodiments, as one example of thecellular communication system, the LTE system is described; however, thepresent disclosure is not limited to the LTE system, and the presentdisclosure may be applied to a cellular communication system other thanthe LTE system.

INDUSTRIAL APPLICABILITY

As described above, the communication control method, the base stationand the user terminal according to the present disclosure are possibleto effectively utilize a wireless LAN access point, and thus are usefulfor a mobile communication field.

1. A communication control method, comprising: transmitting, from a basestation to a user terminal, a plurality of identifiers of wireless LANaccess points and information on a security key to be used in a wirelessLAN communication, notifying the base station, by the user terminal, offirst information indicating a successful connection, in response to asuccessful connection to a predetermined wireless LAN access pointindicated by an identifier included in the plurality of identifiers, andnotifying the base station, by the user terminal of second informationindicating an unsuccessful connection, in response to an unsuccessfulconnection to all of the wireless LAN access point indicated by theplurality of identifiers.
 2. A user terminal configured to connect toabase station, which is configured to perform cellular communication,comprising: a receiver; and a transmitter; wherein the receiver isconfigured to receive, from the base station, a plurality of identifiersof wireless LAN access points and information on a security key to beused in a wireless LAN communication, and the transmitter is configuredto: notify the base station of first information indicating a successfulconnection, in response to a successful connection to a predeterminedwireless LAN access point indicated by an identifier included in theplurality of identifiers; and notify the base station of secondinformation indicating an unsuccessful connection, in response to anunsuccessful connection to all of the wireless LAN access pointindicated by the plurality of identifiers.
 3. A processor forcontrolling a user terminal configured to connect to a base station,which is configured to perform cellular communication, comprising: amemory communicatively coupled to the processor and includinginstructions, such that when executed by the processor performs theprocesses of: receiving, from the base station, a plurality ofidentifiers of wireless LAN access points and information on a securitykey to be used in a wireless LAN communication, and notifying the basestation of first information indicating a successful connection, inresponse to a successful connection to a predetermined wireless LANaccess point indicated by an identifier included in the plurality ofidentifiers; and notifying the base station of second informationindicating an unsuccessful connection, in response to an unsuccessfulconnection to all of the wireless LAN access point indicated by theplurality of identifiers.